Had a chance over the weekend to install 1.0.1, so I'm in a position to report back now.
My upgrade didn't start off too well - i couldn't get the the firmware upgrade process to work… I would get about 7-8mb through the upload, and the connection would fail. Tried from 3 1/2 different browsers and two different operating systems, all with the same results. However, i just did a fresh install from CD, so it wasn't too much of an issue. The users quickly pointed out what NAT rules i had forgotten. :-)
I tested and confirmed the bug before starting: plugged in and enabled the bge interfaces, and watched as the box crashed. After reinstalling, I set up bge1 as WAN2, and managed to pump all my traffic through it without any problems. I'm still in the throws of configuring it, but i currently have 3 interfaces up and running, and i pumped 100mb through bge1 at ~6mb/s during testing, so I'm fairly confident that it works OK now.
I haven't really tested bge0 - as the consensus on forums seems to be that better luck is had with the 2nd interface - however i did plug it in and get a link without the box going down, so it looks promising. No biggie for now, as we don't have a DMZ yet. I will let you know if it works when it comes time to implement it though. :-)
I didn't have to play with IRQs, or disabling iLO (which is good, as i use it) - though those points are worth remembering come DMZ time.
I, too, will give some more feedback once I've been able to heavily work the interface. I can't yet say for certain that it's functioning in a fast and reliable fashion, but as my magic 8-ball would say, 'All signs point to yes'!!